Abstract
Introduction: White spot lesions (WSL) are a common consequence of orthodontic treatment. Remineralization of these
WSLs can take place when calcium and phosphate ions are supplied from an external source to the tooth to promote ion
deposition into crystal voids in demineralized enamel, producing a net mineral gain.
Materials And Method: Strontium fluorapatite was synthesised by green synthesis of Equisetum arvense and Laminariales.
Extracts were mixed with hydroxyapatite and strontium chloride to produce strontium and hydroxyapatite nanoparticles
(NPs). UV-vis spectroscopy was used to detect the formation of NPs. Post spectroscopic analysis, the two mixtures were
then added together and 0.090g of fluorine was added. FTIR spectroscopy and SEM-EDX analysis for surface
characterisation and elemental analysis of the NPs were performed.
Result: Colour change was observed after stirring the mixture on a magnetic stirrer indicating the formation of NPs. UV –
Vis spectroscopic analysis showed sharp peaks at 375 nm wavelength which corresponds to the surface plasmon resonance
band of the strontium fluorapatite NPs. FTIR spectroscopy showed peaks resonating with the different elements of the
NPs. The SEM-EDX analysis shows rod-like particles depicting the presence of strontium. Some spherical shaped
agglomerates corresponded to the hydroxyapatite NPs. The composition obtained from EDAX analysis was Strontium (7.6
Wt%), Fluorine (5.4 Wt%), Calcium (9.4 Wt%) and Phosphorus (4.2 Wt%).
Conclusion: Within the limitations of this study, we can conclude that strontium fluorapatite NPs can be effectively
produced by green synthesis using plant extracts of Equisetum arvense and Laminariales. Future scope for the study
includes investigating the biocompatibility of the NPs to be incorporated into consumer products which would prove to be
beneficial in remineralising white spot lesions.

Key words: Strontium fluorapatite, green synthesis, nanoparticle, horsetail, kelp, white spot lesions